I think you are correct, the space where the alternator lives on a 1800 is a nightmare. I am surprised that one will last as long as they do. The small design of the alternator also works against it's life. Not much room for an effective fan or heatsinks.
Some creative air ducting could do wonders for cooling.
Not sure what Surbuban fuel mileage has to do with it, but thanks for the info.